Fishing lures are classified as spinners, plugs, spoons or attractants depending upon placement in relation to the hook and the motion that they make when drawn through the water. A spoon is placed directly above the hook and in most cases is intended to wobble from side to side when drawn through the water. As the spoon is drawn through the water it may occasionally turn over temporarily exposing its underside and then rights itself.
It is known to make spoons of a reflective metal such as silver, brass, or copper. These lures are intended to catch the fish's attention as light would reflect off the spoon as it does off the silvery scales of some varieties of fish. More recently, spoons have been manufactured which are painted on one side, and on the other have a reflective metal surface. These types of spoons attempt to combine the reflective qualities which characterize the known style of lure with the realities that fish and the food they feed on in their natural environment are multi-colored. Some types of spoons have an added transparent coating of plasticised material in order to preserve the spoon from rust or corrosion.
Studies have been conducted by a number of zoologists, the most notable of which is Dr. Loren Hill, the chairman of the Department of Zoology at the University of Oklahoma into the "color vision" of fish. Dr. Hill concluded that fish rely upon color vision for food selection, as well as for other aspects of their existence, such as mating behaviour. His research has concluded that fish can distinguish between colors in the electro-magnetic spectrum and, in fact, readily distinguish between closely related colors or shades of the same color. The fish's eye is apparently more sensitive to light than a human eye, thus allowing the fish to distinguish under varying water clarity and lighting conditions, colors the human eye cannot. Dr. Hill has developed under the trade name "Color-C-Lector" an under water probe and complementary color charts to assist fishermen on the selection of the correct color of spoon depending upon the season, feeding habits of particular varieties of fish, water depth where the fish are normally found and water temperature. Much is yet to be discovered regarding color and its effect on the effectiveness of spoon, however, it is apparent that the color of the spoon used is an important determinant in the success of a fisherman.
It is logical that a spoon will be more effective if the light striking it causes it to more closely resemble the qualities of the natural prey of the species of fish being sought. It is by comparing the colored spoons with fish larva which serve as the natural prey of the fish that the short comings of the spoon becomes apparent. All fish larva start out as translucent and gradually acquire their coloration. As they mature, portions of the fish larva become opaque such as the bones and internal organs. Once they have grown beyond the larva stage, most species of fish are still translucent to a greater or lesser degree. Existing spoons imitate the coloration and reflective qualities of the scales, but they do not try to imitate the effect of light rays passing through a multi-colored fish. Light rays passing through a partially translucent colored object give the water a colored aura in the vicinity of the object.